Greenhouse Question

dvtown(6b)October 26, 2009

I know there is a greenhouse forum but I thought my fellow Tennessee gardeners might have more relevant information for my question. I'm building a 12x16 greenhouse-shed right now. I found lots of windows on Craigslist and have a considerable amount of work done already. My question is on temperatures. For those who have greenhouses what kind of temperature extremes do you find yourself with during the winter? Daytime temps vs. night time temps. I'm curious since I'm currently researching insulation to put in. I want to reduce my heat loss as much as possible to reduce heating costs.

I designed a few plans based on some shed designs I researched only. It's more than a basic sketch. I do have the advantage of having a structural engineer for a father-in-law so he offered some input to make sure it stood up.

I put a link to it's current progress. There are some other links to previous posts to show the build process if you are interested.

Dave on clear bright sunny days it will still get warm inside in the winter. My exhaust fan is still kicking on with this cool weather we are having now. I have four 55 gal drums (painted black) filled with water, they get warm in the day and release a little heat back at night.I place them on the north wall and use the top of them for a shelf. I have a gas heater set at about 50 or 55 degree for the night. Dont't know how you are going to insulate much unless you use double wall construction. I keep a fan running 24 hours a day for circulation. I know this did not answer your guestions but thats my set up, hope it gives you some ideas.
Norm

I've thought of the passive heat option some. My goal is to have this running for spring seed starting with appropriate temperatures for those. My disadvantage is the distance from the house. I don't plan on running power or lines out there so a gas heater might be necessary. How does the cost of running a gas heater work out? I'm sure it depends on how much is being heated I'll need to heat less than 200 sq feet. I've been planing on insulating the sides and non glass areas of the roof. Construction is much more shed-like with a bunch of windows so I should be able to add insulation to some areas. I'm considering the foil insulation types to reduce heat loss.

Dave mine is 8X20 built against my garage,on the south side. I use a small propane heater. Since I have my house running on propane, I don't have any idea how much it cost for the green house. I just enjoy. Here is something I learned the hard way. Plastic against a dark colored object, gets hot at that point and heat will ruin the plastic in two or three years. Try to cover corner post and ridges with something white. I like the woven plastic for the roof, it sends the light rays in all directions, and is very tough stuff.
Norm

Just a guess Steve but I think your heater would keep in the 50 or 55 degree range, on cold nights, I have used a heater like that for a backup and it saved me when the pilot light went out in the gas heater.
Norm

Steve are you keeping yours indoors or out? I have a 4 shelf plastic covered one I keep in the garage by a window. I usually don't need to do anything for heat but I just overwinter cuttings in there rather than seed start. I've been seed starting in the house but hopefully not for much longer!